1. Field of the Invention
The present invention relates to an ink reservoir for an ink jet recording apparatus, and, more particularly, it is concerned with an ink reservoir for an ink jet recording apparatus, which has solvent problems in connection with an ink storing tank and the disposal of a waste ink collecting tank.
2. Related Background Art
A polychromatic ink jet printer is provided with a plurality of ink cassettes, each containing therein an ink tank which stores different colors of ink. These ink cassettes are installed in the printer in a freely mountable and dismountable manner. The inks in various colors stored in the ink cassettes are used for printing numerical figures and letters, or for producing picture images in monochrome or in polychrome using the various ink colors in combination. The colors of the ink which are typically used are cyan, magenta, yellow and black. For letter printing, black ink is usually used. For picture images output, black and the three other colors in combination are used.
For a color ink jet printer utilizing black ink color inks, the U.S. Pat. No. 4,695,824 proposes to provide a unit for holding waste ink by absorption only of ink in the black ink cartridge, thereby disposing of the waste ink by the replacement of the black ink cartridge that has a higher frequency of use and replacement thus achieving compactization of the apparatus.
Also the U.S. Pat. No. 4,437,104 proposes to provide a cartridge incorporating three color inks with an integral ink absorbent material. Such a structure, however, does not allow appropriate replacement of each color ink since all the inks used in the apparatus are incorporated in a single cartridge, and the ink absorbent material has to be made large in consideration of the amount of waste ink from the cartridge.
The present inventors have found that such conventional structures give rise to new drawbacks in case of a full-color printer or a multi-color printer.
As the result of the increase in full-color recording, the collection of all the waste ink in a black ink cartridge may not be appropriate, as the ink cartridge may have to be replaced when the amount of waste ink exceeds the absorbing capacity of the ink absorbent material even if a considerable amount of black ink still remains in the cartridge.
Also the waste ink reservoir of the black ink cartridge may cause overflow if the color ink cartridges are replaced frequently. Furthermore, when the cartridges are divided into plural colors, it is necessary to provide a waste ink reservoir separately and provide alarming means therefor. Such a arrangement diminishes the convenience of use and complicates the structure of the device.
Also in case of plural cartridges of the same color (including the case of ink of different densities), there may result overflowing or wasting of ink.